This invention generally relates to methods and systems for reducing the risk of patient bloodstream infection by microorganisms during administration of various medications and fluids through lines. In particular, the invention relates to methods and systems for reducing the count of infectious agents and inhibiting the growth of microorganisms inside intravenous (IV) lines and accompanying connectors, stopcock valves, ports and tubes.
It is a common practice in medicine to administer various medications and fluids into and withdraw blood from a patient's vascular system. For these purpose, various intravenous access devices exist. Such a device typically has a hollow needle, the tip of which is inserted into a patient's blood vessel for variable periods of time—from seconds (for example, injections and blood sampling) to years (for example, total parenteral nutrition, chemo-therapy and dialysis). All such devices bypass several natural anti-infection defense barriers and introduce a risk of direct bloodstream contamination. The general terms for these devices is “lines.” The type of infection that arises from the use of such “lines” is called “line sepsis.” Elaborate and complicated precautions and prevention techniques are in use, and include use of one or more of the following means: sterile equipment, sterile insertion technique, aseptic handling techniques, replacement of the “lines” as indicated by various protocols, antibiotics, and antibacterial substances impregnated into catheters.
One of the unsolved problems that is especially relevant to intravascular catheters with longer time of use is colonization by microorganisms of the catheter itself and its associated connectors, stopcocks, ports, valves and tubes. The methods of cleaning and disinfecting indwelling catheters and associated tubes, valves and connectors are of low efficacy, and for that reason, in cases of suspected contamination the components are preferably replaced or removed. Decontamination of indwelling devices and associated valves, ports, connectors and tubing is very problematic because the patient, his blood, and the administered medicine are potentially exposed to all of the physical, chemical and pharmacological effects of such decontamination.
One currently available method of keeping the line components, such as stopcock valves, free of microbiological contamination uses silver ions embedded in the stopcock device. Products such as Elcam Medical Inc.'s antimicrobial stopcocks provide two layers of protection: (i) a closed system designed to prevent contaminants' penetration into the stopcock fluid path and thereby reduce the risk of bloodstream infections; and (ii) silver ions to reduce and prevent bacteria colonization on the product.
The disadvantages of using silver ions and chlorhexidine technology are the following: (a) It starts to act only after the polymer with embedded silver ions is in a wet condition and is active for a minimum of 6-8 hours, while during that time microorganisms already start to grow and multiply. (b) It relies on disinfection materials that are present only in the area close to the flow path walls and that wash away when the line is flushed. (c) The quantity of disinfection material that is effective is declining as time passes, whereas the risk of contamination rises as time passes. (d) The technology is limited only to polymers that can be impregnated or applied as a coating.
Another known method for sterilizing the connection junctions of tubing connecting a catheter to a solution container is to expose the connection junctions to ultraviolet radiation. For example, U.S. Pat. No. 4,412,834 discloses antimicrobial ultraviolet irradiation of connectors for continuous ambulatory peritoneal dialysis.
There is a need for improved apparatus and improved methods for reducing the risk of patient bloodstream infection by microorganisms during administration of various medications and fluids through lines and during the withdrawal of blood samples. This need is especially great at those sites in intravenous access systems where stagnation occurs.